1. Field of the Invention
The present invention relates generally to agricultural planting equipment. More specifically, an embodiment of the present invention concerns a twin-row planter including relatively adjustable seed metering assemblies of each planting unit pair for permitting selective variance of the seed stagger in the adjacent furrows.
2. Discussion of Prior Art
Conventional row-crop planters include a plurality of planter units for planting seeds along spaced-apart rows. Some of these conventional planters include a single planter unit per row that plants seeds along a single furrow. Other planters known in the art include two planters per row and are referred to as twin row seed planters. Twin row planters enable the placement of seed along two closely-spaced furrows within the corresponding row. In particular, twin row planters can discharge seeds into an alternating pattern between adjacent furrows within the row, i.e., the two planters alternately position seed. In this manner, twin row planters enable a greater number of seeds to be planted along the row than single row planters while maintaining the necessary spacing between individual seeds.
Twin row planters are problematic and suffer from various undesirable limitations. It is highly desirable to have the seeds in the closely-spaced furrows to be relatively positioned in a desired pattern. Typically, this pattern constitutes equidistant spacing (i.e., uniform staggering) of the seeds between the furrows. However, the problem is that if the speed of the drive mechanism relative to the ground speed is changed, the stagger between adjacent furrows changes. In some instances, seeds from the two furrows could be placed immediately adjacent one another. With prior art twin row planters, users have attempted to reconfigure the seed stagger between furrows by adjusting the transmission that interconnected the planter units. In particular, users would shift a drive chain from one position to another on a corresponding sprocket by “jumping the chain off the sprocket.” This technique is problematic because the step of repositioning the chain fails to indicate the resulting seed stagger pattern. As a consequence, the user of this method typically must observe the pattern resulting from the chain adjustment and then, if necessary, make additional adjustments to the transmission to achieve the desired pattern. This iterative method requires guesswork by the user and is commonly very time consuming, imprecise, and difficult to repeat for subsequent planter pairs.